The process of bacterial growth and cell division is of fundamental importance to all aspects of bacteriology, from the proliferation of bacteria during the establishment of an infection by a pathogen in man to the multiplication of a saprophyte in soil. Although there have been tremendous advances made in our knowledge of the biosynthetic pathway for cell wall associated macromolecules, details of how the bacterial cell orchestrates this process are still rudimentary. The objective of our work is to identify and characterize gene products which function in the cell division process. We have selected the Gram-positive rod shaped bacterium, Bacillus subtilis, for these studies. A number of mutants of this organism are available which are defective in a specific aspect of the division process. To understand the nature of the biochemical defect associated with these cell division mutants, the genes represented by these mutations will be cloned and their gene products identified. The method of approach will be to position a transposon near a particular gene and then clone this region of the Bacillus chromosome, utilizing the antibiotic resistance gene on the transposon to provide the selective marker for the cloning. Once the product of a cell division gene has been identified, its intracellular distribution will be determined utilizing immunoelectron microscopy. The nature of cell division gene regulation, at the transcriptional and translational levels, will also be examined by means of hybridization and immunoprecipitation analyses. In vitro mutagenesis procedures will be employed in an effort to identify genes which function in the cell division process but which are not represented by the currently available collection of B. subtilis mutants. From this work we hope to gain a better understanding of how the bacterium carries out the orderly processes of growth and cell division. Furthermore, the question of how these events are regulated could then be addressed.